1. Field of the Invention
The present invention relates generally to a cushion insert for a clamp assembly for securing elongate cylindrical members, such as pipe, conduit, tubing or hose, to a support surface, and more particularly, to a two-piece cushion insert for a U-bolt clamp assembly for securing large diameter elongate cylindrical members therein.
2. Description of Related Art
Presently, there exists a clamp assembly for securing an elongate cylindrical member to a support surface having a one-piece, split-sleeve, shock absorbing cushion insert, a U-shaped rod member and fastening means. The cylindrical member is encompassed by the cushion insert which is, in turn, adapted to be retained by the U-shaped rod member. When the U-shaped rod member is secured to the support surface by the fastening means, the clamping force generated by the U-shaped rod member is distributed about a circumferential section of the cylindrical member by the cushion insert.
An example of such a clamp assembly is disclosed in U.S. Pat. No. 5,014,940, issued May 14, 1991, by Inventor Clarence A. Sherman, the disclosure of which is hereby incorporated by reference. As shown in FIG. 1, the patented clamp assembly 10 includes an injection molded, elastomeric, one-piece cushion insert 12 for circumferentially engaging the cylindrical member 14 which is retained within the clamp assembly 10 by a U-bolt 16. The cushion insert 12 of the '940 patent comprises a generally planar base portion 18 with upwardly and inwardly extending arcuate side walls 20 that combine to define a passageway 22 which extends axially through the cushion insert 12. At the top of the passageway 22 is an axial gap 24 that separates the side walls 20. Located in the base portion 18, opposite from the gap 24, is an axial slot 26 which acts as a hinge. The gap 24 and the slot 26 operatively cooperate to allow the cushion insert 12 to flex and be adapted to fit about the cylindrical member 14. The base portion 18 and side walls 20 also have an arcuate saddle for accommodating the U-bolt 16 so that the U-bolt 16 is secured relative to the cushion insert 12 and the clamping force generated by the U-bolt 16 is distributed about a circumferential section of the cylindrical member 14 which is encompassed by the cushion insert 12.
One disadvantage of the cushion insert used in the clamp assembly described above is that in certain applications where the cylindrical member desired to be secured by the clamping assembly is of sufficiently large diameter, an extremely large force is required to flex the side walls of the cushion insert sufficiently apart to enable the cushion insert to fit over and about the cylindrical member, regardless of the presence of a "hinge." A further disadvantage of the prior known cushion insert of the type discussed is that the manufacturing of the cushion insert in sizes that can accommodate large diameter cylindrical members becomes economically impractical.
It is, therefore, one object of the present invention to provide an economical and easy-to-use two-piece cushion insert for use in a U-bolt clamp assembly which can be used for tubing, pipes and other cylindrical members having diameters of up to at least twenty four inches.
It is another object of the present invention to provide a two-piece cushion insert for use in a U-bolt clamp assembly that can transmit the clamping force of the U-bolt along the entire width of the cushion insert surface that is in engagement with the cylindrical member.
It is a further object of the present invention to provide a cushion strip of a uniform cross-section for use in a U-bolt clamp assembly that can be cut to the appropriate length for a variety of cylindrical member sizes.